The invention relates generally to reclosable fasteners and a method of forming a reclosable fastener profile assembly which allows for fast, automated production and accurate, seal registration. In particular, the invention relates to a seal arrangement for a reclosable zipper profile strip, which is created through the application of heat and pressure to a male and female profile to form a ‘compression molded segment’ seal, and to a method of producing such a seal.
The popularity of reclosable zipper fasteners has created a demand for a large number and wide variety of reclosable bag sizes and types. It is commonly known in the art to form a reclosable bag through the addition of a zipper profile to a pair of bag walls in order to form a bag with a reclosable, airtight seal. However, improper registration may cause the seal to weaken and fail over time or become permeable to the air. In many reclosable bag applications, an airtight seal is necessary to maintain the freshness of articles placed in the bag. Further, such seals must be suitable for high-speed automated production in order to make the production of reclosable bags commercially viable.
In the case of zipper profiles, commonly known methods of construction and seal formation often cause inaccurate, commercially unacceptable seals which cannot be produced on an economically practical scale. Commonly known profile formation methods in the art require multiple sealing devices, precise machinery or extensive retooling to alter the size and type of reclosable fastener. Exemplary devices are shown and described in U.S. Pat. Nos. 5,601,368 (Bodolay); 3,847,711 (Howard); 5,461,845 (Yeager); 5,823,933 (Yeager); 4,241,865 (Ferrell); 4,335,817 (Bahr); 4,909,017 (McMahon); and 5,024,537 (Tilman). As such, none of the devices referenced above satisfy the need for a multi-purpose reclosable zipper profile, which can be accurately and economically manufactured.
Therefore, an unfulfilled need remains for a zipper profile which can be accurately manufactured at a high rate of speed and which can be adapted to a wide range of reclosable zipper bag applications.